class MessagePack::Unpacker

static VALUE Unpacker_initialize(int argc, VALUE* argv, VALUE self)
{
    VALUE io = Qnil;
    VALUE options = Qnil;

    if(argc == 0 || (argc == 1 && argv[0] == Qnil)) {
        /* Qnil */

    } else if(argc == 1) {
        VALUE v = argv[0];
        if(rb_type(v) == T_HASH) {
            options = v;
            if(rb_type(options) != T_HASH) {
                rb_raise(rb_eArgError, "expected Hash but found %s.", rb_obj_classname(options));
            }
        } else {
            io = v;
        }

    } else if(argc == 2) {
        io = argv[0];
        options = argv[1];
        if(rb_type(options) != T_HASH) {
            rb_raise(rb_eArgError, "expected Hash but found %s.", rb_obj_classname(options));
        }

    } else {
        rb_raise(rb_eArgError, "wrong number of arguments (%d for 0..2)", argc);
    }

    UNPACKER(self, uk);

    MessagePack_Unpacker_initialize(uk, io, options);

    return self;
}

static VALUE Unpacker_buffer(VALUE self)
{
    UNPACKER(self, uk);
    return uk->buffer_ref;
}

static VALUE Unpacker_each(VALUE self)
{
    UNPACKER(self, uk);

#ifdef RETURN_ENUMERATOR
    RETURN_ENUMERATOR(self, 0, 0);
#endif

    if(msgpack_buffer_has_io(UNPACKER_BUFFER_(uk))) {
        /* rescue EOFError only if io is set */
        return rb_rescue2(Unpacker_each_impl, self,
                Unpacker_rescue_EOFError, self,
                rb_eEOFError, NULL);
    } else {
        return Unpacker_each_impl(self);
    }
}

static VALUE Unpacker_feed(VALUE self, VALUE data)
{
    UNPACKER(self, uk);

    StringValue(data);

    msgpack_buffer_append_string(UNPACKER_BUFFER_(uk), data);

    return self;
}

static VALUE Unpacker_feed_each(VALUE self, VALUE data)
{
    // TODO optimize
    Unpacker_feed(self, data);
    return Unpacker_each(self);
}

static VALUE Unpacker_read(VALUE self)
{
    UNPACKER(self, uk);

    int r = msgpack_unpacker_read(uk, 0);
    if(r < 0) {
        raise_unpacker_error(r);
    }

    return msgpack_unpacker_get_last_object(uk);
}

static VALUE Unpacker_read_array_header(VALUE self)
{
    UNPACKER(self, uk);

    uint32_t size;
    int r = msgpack_unpacker_read_array_header(uk, &size);
    if(r < 0) {
        raise_unpacker_error(r);
    }

    return ULONG2NUM(size);
}

static VALUE Unpacker_read_map_header(VALUE self)
{
    UNPACKER(self, uk);

    uint32_t size;
    int r = msgpack_unpacker_read_map_header(uk, &size);
    if(r < 0) {
        raise_unpacker_error((int)r);
    }

    return ULONG2NUM(size);
}

static VALUE Unpacker_reset(VALUE self)
{
    UNPACKER(self, uk);

    _msgpack_unpacker_reset(uk);

    return Qnil;
}

static VALUE Unpacker_skip(VALUE self)
{
    UNPACKER(self, uk);

    int r = msgpack_unpacker_skip(uk, 0);
    if(r < 0) {
        raise_unpacker_error(r);
    }

    return Qnil;
}

static VALUE Unpacker_skip_nil(VALUE self)
{
    UNPACKER(self, uk);

    int r = msgpack_unpacker_skip_nil(uk);
    if(r < 0) {
        raise_unpacker_error(r);
    }

    if(r) {
        return Qtrue;
    }
    return Qfalse;
}